According to an "Coach and Chassis" Q/A in the May 2007 issue of Motorhome magazine, a person asked about leaving the MH plugged in. The response stated that the batteries would "sulfate and derate" if a (typical) 13.5 volt charge is left on for an extended period. I have always left my MH plugged in year round and I have not seen any signs of sulfation in the batteries. I guess I am missing something?

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According to an "Coach and Chassis" Q/A in the May 2007 issue of Motorhome magazine, a person asked about leaving the MH plugged in. The response stated that the batteries would "sulfate and derate" if a (typical) 13.5 volt charge is left on for an extended period. I have always left my MH plugged in year round and I have not seen any signs of sulfation in the batteries. I guess I am missing something?

my motorhome is plugged in 24-7-365. the battery charger has an equalize setting so it is switched on every 6 months to equalize and desulfate the batteries. i usually get 6 years out of the batteries before i have to replace them. 4- 6 volt golfcart and 2- 12 volt size 31.
they all get charged at the same time.
1996 kountrystar dp

As RV Wizard said, it depends on the system being used to do the charging. If it's a 3 stage inverter/charger system it's not a problem. However, it's best that the coach and it's electrical system and batteries get some use too.

thanks for the heads up , I wasn't sure myself. I only plug in the motorcoach in the driveway the day before a road trip to get the refer going I had a electrican put in a dedicated outside box about 5 feet from the rear driver side for the shore power plug to give it a little charging. Then I use a separate 110 volt 10 amp charger for giving the coach batteries a good charge . That is what a old full timer in a 40 foot pusher told me to do .

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BigRedLancer:
How do I determine the type of charging system (two/three stage?) in the coach. I don't use an external charger. </div></BLOCKQUOTE>
Look at the label on the inside of the cover of your inverter/charger. It will give the model number, and the power rating (120VAC input: 12 VDC output: 2 or 3 stage and what amperage of each stage. When you open the cover you'll find the fuses and circuit breaker switches for all the electrical circuits in your rig.

If all else fails, you might read the owner's manual for the inverter/charger that came with the unit. I couldn't resist...

Well. I didn't get any docs on the converter/charger. I looked at the converter and it states it puts out 13.5VDC with 120VAC input. Nothing about "stages" anywhere on the unit.

Just checked on the web and discovered the converter/charger that I have is a single stage. A two stage converter uses a timer to start the voltage at 14 and then drops it to 13.5 after a predetermined length of time. This is supposed to help reduce sulfation. I guess I will have to just keep an eye on the house batteries.

While a 3 stage charger with a "battery tender" to monitor the battery temperature (got both now) is ideal; I spent many years with a single stage charger. I am pluged in 95% + of the time. I had 4 6V Trojan T-105's for house batteries. They lasted approximately 5 years before being replaced. Make it a rule to check and fill your batteries every month!

We leave our coach connected to shore power when home, but since we have a 110w solar panel with a Solar Boost 2000E controller I shut the converter off. The solar panel adequately maintains our 6 coach batteries and on a full sun day, voltage output is around 14v, however when batteries are fully charged the amperage output drops to 1.4amps. So far it works great, using the "Pro-Fill" system I check the water every 2 to 3 weeks and add if needed.